Ultrafine and polar ZrO2-inlaid porous nitrogen-doped carbon nanofiber as efficient polysulfide absorbent for high-performance lithium-sulfur batteries with long lifespan

摘要

The limitations of low active material utilization, severe capacity fading and short lifespan, mainly resulting from the intermediate polysulfides shuffling, have been hampering the development and practical applications of the lithium-sulfur (Li-S) battery technology. To overcome these issues, a porous nitrogen-doped carbon nanofiber membrane containing ultrafine and polar ZrO2 (CNF@ZrO2 ) has been investigated as a promising polysulfide host in Li-S batteries. The CNF@ZrO2 interlayer not only serves as a high efficiency lithium polysulfide barrier to suppress the side reactions which is further demonstrated by molecular modeling studies, but also functions as an upper current collector which can enhance the polysulfide redox reactions. Thereby, Li-S batteries with high capacity, prolonged cycle life and stable reversible cyclability can be achieved. A negligible capacity fading rate of 0.039% per cycle over 500 cycles at 0.2 C is obtained. This work offers a facile and effective method of promoting Li-S batteries for practical applications.